In existing vehicle washing systems, a plurality of generally cylindrical brushes are mounted about vertical axes and are rotated to scrub a vehicle as the vehicle is propelled through a washing station. Some or all of the brushes are mounted upon the free ends of rotatable arms which are bifurcated at their free ends to receive the axles about which the brushes rotate and which are fastened to a washing station framework for lateral rotation with respect thereto. These arms are biased into contact with a side of a vehicle passing through the station. In addition, certain of the brushes may be biased to press inward behind the vehicle once the vehicle has passed the brush position in order to clean the rear of the vehicle. However, it has been found that existing systems inadequately wash the rear surfaces of vehicles. Since the vehicle is moving forward and the brushes are pressed either to the rear or inwardly from the sides, conventional brushes make minimal contact with the rear of the vehicle.